I had never paid close attentionto the guilloche on the dial of the Malte Tonneau Dual Time just considering it as a diamond shaped patter. A few days ago I got to spend some time with one and upon closer attention the dial guillochage is not at all "only" a diamond shape but rather a rather complex cubic pattern which reminds me somewhat of those in Vasarely's paintings.
The fact that there are different guilloche patterns one one surface (as in different patterns in different subdials) the guillochage of this dial is not only extremely difficult to do but also extremely time consumming!!
Kudos to the guillocheur
Chess by Vasarely